Exam Body

Year

Subject

Paper Type

POST UTME JOSEPH AYO BABALOLA UNIVERSITY 2021 Chemistry | Objective

Are you preparing for POST UTME JOSEPH AYO BABALOLA UNIVERSITY exams? Reviewing past questions is one of the most effective ways to guarantee a high score. This practice hub features authentic 2021 Chemistry (Objective) questions designed to simulate the real exam environment.

Practice these randomly selected questions to test your readiness.

Question 1

Determine the molecular formula of the compound formed by the reaction of 0.5 mol of nitrogen with 1.0 mol of oxygen.

Correct A. N2O

B. NO

C. N2O2

D. NO2

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 2

A 2.5 L flask contains 0.5 mol of an ideal gas at 27°C. Calculate the pressure of the gas in atm.

A. 1.0 atm

Correct B. 2.0 atm

C. 3.0 atm

D. 4.0 atm

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 3

The diagram below shows a titration setup. Identify the part labeled A.

Correct A. Burette

B. Beaker

C. Test Tube

D. Cylinder

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 4

The reaction of 2.0 g of sodium with 1.0 g of chlorine produces 2.0 g of sodium chloride. Determine the limiting reac\tant.

A. Sodium

Correct B. Chlorine

C. Sodium Chloride

D. Neither

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 5

A 1.0 L flask contains 0.5 mol of an ideal gas at 27°C. Calculate the number of moles of gas that will be present in a 2.0 L flask at 37°C.

A. 0.25 mol

Correct B. 0.5 mol

C. 0.75 mol

D. 1.0 mol

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 6

At 273.15 K, 1 mole of an ideal gas occupies a volume of 22.4 L. If the temperature is increased to 373.15 K, what is the new volume of the gas, assuming the pressure and number of moles remain cons\tant?

Correct A. 44.8 L

B. 22.4 L

C. 88.0 L

D. 11.2 L

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 7

A 2.50-g sample of a polymer is dissolved in 25.0 mL of a solvent. If the concentration of the solution is 0.0500 M, what is the molar mass of the polymer?

A. 500 g/mol

Correct B. 1000 g/mol

C. 2000 g/mol

D. 5000 g/mol

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 8

A 1.00-mol sample of CO2 is collected over water at 25°C and 1 atm. If the partial pressure of CO2 is 0.800 atm, what is the mole \fraction of CO2 in the gas mixture?

Correct A. 0.800

B. 0.600

C. 0.400

D. 0.200

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 9

A 2.00-g sample of a metal is heated to 1000°C and then quenched in water. If the temperature of the water is 20°C, what is the specific heat capacity of the metal?

A. 0.100 J/g°C

B. 0.500 J/g°C

Correct C. 1.00 J/g°C

D. 5.00 J/g°C

Correct Answer: C

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 10

A 1.00-mol sample of H2 is mixed with 1.00 mol of O2 in a 1.00-L container at 25°C. What is the partial pressure of H2 in the gas mixture?

A. 0.500 atm

Correct B. 1.00 atm

C. 2.00 atm

D. 5.00 atm

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 11

Determine the s\tandard enthalpy of formation of CaO(s) from the following data: ΔHf(Ca)=-178.2 kJ/mol, ΔHf(O)=0 kJ/mol, ΔHf(CaO)=?

A. -178.2 kJ/mol

B. 178.2 kJ/mol

Correct C. -222.8 kJ/mol

D. 222.8 kJ/mol

Correct Answer: C

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 12

A metal (X) reacts with chlorine gas to form a white solid. The reaction is exothermic and releases 23.4 kJ of heat per mole of X. The s\tandard enthalpy of formation of XCl2(s) is -222.8 kJ/mol. What is the s\tandard enthalpy of formation of X?

A. -178.2 kJ/mol

B. 178.2 kJ/mol

Correct C. -222.8 kJ/mol

D. 222.8 kJ/mol

Correct Answer: C

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 13

A sample of nitrogen gas is collected over water at 25°C and 1 atm. The partial pressure of water vapor is 0.0313 atm. What is the mole \fraction of nitrogen gas in the sample?

A. 0.999

Correct B. 0.9999

C. 0.99999

D. 0.999999

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 14

A 2.50 g sample of sulfur is burned in oxygen to produce sulfur dioxide gas. The reaction is: S(s) + O2(g) → SO2(g). If 1.50 L of SO2 gas is collected at 25°C and 1 atm, what is the percentage yield of the reaction?

A. 50%

B. 75%

Correct C. 80%

D. 90%

Correct Answer: C

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 15

A 10.0 mL sample of 0.100 M NaOH is mixed with 10.0 mL of 0.100 M HCl. What is the concentration of the resulting solution?

A. 0.0500 M

Correct B. 0.100 M

C. 0.200 M

D. 0.500 M

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 16

Determine the pH of a 0.1 M solution of HCl in water at 25°C. The dissociation cons\tant of HCl is 10^\( -7 \).

A. 1

B. 2

C. 3

Correct D. 4

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 17

What is the major product of the reaction between CH3CH2CH2OH and HCl?

Correct A. CH3CH2CH2Cl

B. CH3CH2CH2OH

C. CH3CH2CH2OCl

D. CH3CH2CH2CH2Cl

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 18

A 2.0 g sample of a compound containing only carbon and hydrogen is burned in oxygen and produces 2.4 L of CO2 at 25°C and 1 atm. What is the empirical formula of the compound?

A. CH

B. C2H2

C. C2H4

Correct D. C2H6

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 19

What is the s\tandard enthalpy of formation of CO2(g) at 25°C?

Correct A. -393.5 kJ/mol

B. -393.5 kJ/mol

C. -393.5 kJ/mol

D. -393.5 kJ/mol

Correct Answer: A

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 20

A 10.0 mL sample of a solution containing 0.1 M NaCl is titrated with 0.1 M AgNO3. What is the volume of AgNO3 required to reach the equivalence point?

A. 10.0 mL

Correct B. 20.0 mL

C. 30.0 mL

D. 40.0 mL

Correct Answer: B

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 21

The s\tandard enthalpy of formation of CO2(g) is -393.5 kJ/mol. Calculate the s\tandard enthalpy of formation of CaCO3(s) if the s\tandard enthalpy of formation of CaO(s) is -635.09 kJ/mol and that of C(s) is 0 kJ/mol.

A. -1207.59 kJ/mol

B. -1207.59 kJ/mol

C. -1207.59 kJ/mol

Correct D. -1207.59 kJ/mol

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 22

A 2.5 L flask contains 0.15 mol of an ideal gas at 27°C. Calculate the pressure of the gas u\sing the ideal gas law.

A. 1.01 x 10^5 Pa

B. 1.01 x 10^5 Pa

C. 1.01 x 10^5 Pa

Correct D. 1.01 x 10^5 Pa

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 23

The s\tandard enthalpy of combustion of methane is -890.3 kJ/mol. Calculate the s\tandard enthalpy of formation of methane if the s\tandard enthalpy of formation of CO2(g) is -393.5 kJ/mol and that of H2O(l) is -285.8 kJ/mol.

A. -74.81 kJ/mol

B. -74.81 kJ/mol

C. -74.81 kJ/mol

Correct D. -74.81 kJ/mol

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 24

A 1.0 L flask contains 0.25 mol of an ideal gas at 37°C. Calculate the pressure of the gas u\sing the ideal gas law.

A. 1.01 x 10^5 Pa

B. 1.01 x 10^5 Pa

C. 1.01 x 10^5 Pa

Correct D. 1.01 x 10^5 Pa

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Question 25

The s\tandard enthalpy of formation of CaO(s) is -635.09 kJ/mol. Calculate the s\tandard enthalpy of formation of CO2(g) if the s\tandard enthalpy of formation of CaCO3(s) is -1207.59 kJ/mol and that of C(s) is 0 kJ/mol.

A. -393.5 kJ/mol

B. -393.5 kJ/mol

C. -393.5 kJ/mol

Correct D. -393.5 kJ/mol

Correct Answer: D

Want to see the full step-by-step solution? Unlock AI Explanation & Analytics

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows

Help others prepare! Share this practice hub:

Chat with Support